U.S. patent application number 15/888257 was filed with the patent office on 2018-12-13 for plasma strip tool with uniformity control.
The applicant listed for this patent is Mattson Technology, Inc.. Invention is credited to Dixit V. Desai, Shawming Ma, Vladimir Nagorny, Ryan Pakulski.
Application Number | 20180358210 15/888257 |
Document ID | / |
Family ID | 64564206 |
Filed Date | 2018-12-13 |
United States Patent
Application |
20180358210 |
Kind Code |
A1 |
Ma; Shawming ; et
al. |
December 13, 2018 |
Plasma Strip Tool With Uniformity Control
Abstract
Plasma strip tools with process uniformity control are provided.
In one example implementation, a plasma processing apparatus
includes a processing chamber. The apparatus includes a first
pedestal in the processing chamber operable to support a workpiece.
The first pedestal can define a first processing station. The
plasma processing apparatus can include a second pedestal in the
processing chamber operable to support a workpiece. The second
pedestal can define a second processing station. The apparatus can
include a first plasma chamber disposed above the first processing
station. The first plasma chamber can be associated with a first
inductive plasma source. The first plasma chamber can be separated
from the processing chamber by a first separation grid. The
apparatus can include a second plasma chamber disposed above the
second processing station. The second plasma chamber can be
associated with a second inductive plasma source. The second plasma
chamber can be separated from the processing chamber by a second
separation grid.
Inventors: |
Ma; Shawming; (Sunnyvale,
CA) ; Nagorny; Vladimir; (Tracy, CA) ; Desai;
Dixit V.; (Pleasanton, CA) ; Pakulski; Ryan;
(Discovery Bay, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Mattson Technology, Inc. |
Fremont |
CA |
US |
|
|
Family ID: |
64564206 |
Appl. No.: |
15/888257 |
Filed: |
February 5, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62610588 |
Dec 27, 2017 |
|
|
|
62517365 |
Jun 9, 2017 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01J 37/321 20130101;
H01L 21/67069 20130101; H01L 21/67207 20130101; H01J 37/32816
20130101; H01J 37/32522 20130101; H01J 37/32834 20130101; H01J
2237/002 20130101; H01J 37/32715 20130101; H01J 37/32899 20130101;
H01L 21/67109 20130101; H01J 37/32422 20130101; H01J 37/32513
20130101; H01L 21/6719 20130101 |
International
Class: |
H01J 37/32 20060101
H01J037/32; H01L 21/67 20060101 H01L021/67 |
Claims
1. A plasma processing apparatus, comprising: a processing chamber;
a first pedestal in the processing chamber operable to support a
workpiece, the first pedestal defining a first processing station;
a second pedestal in the processing chamber operable to support a
workpiece, the second pedestal defining a second processing
station; a first plasma chamber disposed above the first processing
station, the first plasma chamber associated with a first inductive
plasma source, the first plasma chamber separated from the
processing chamber by a first separation grid; a second plasma
chamber disposed above the second processing station, the second
plasma chamber associated with a second inductive plasma source,
the second plasma chamber separated from the processing chamber by
a second separation grid.
2. The plasma processing apparatus of claim 1, wherein the
processing chamber has a wall separating the first pedestal from
the second pedestal, the wall comprising a wall temperature
regulation system.
3. The plasma processing apparatus of claim 2, wherein the wall
temperature control system comprises one or more heating
elements.
4. The plasma processing apparatus of claim 2, wherein the wall
temperature control system comprises one or more cooling
channels.
5. The plasma processing apparatus of claim 1, wherein comprising a
pressure equalizing baffle connected to the plurality of pedestals
operable to maintain pressure between the first processing station
and the second processing station.
6. The plasma processing apparatus of claim 1, wherein the
apparatus comprises a first concentric pump port located beneath
the first pedestal and a second concentric pump port located
beneath the second pedestal.
7. The plasma processing apparatus of claim 6, wherein the plasma
processing apparatus comprises a common pump is coupled to the
first concentric pump port and the second concentric pump port.
8. The plasma processing apparatus of claim 1, wherein the plasma
processing apparatus further comprises a top plate disposed above
the first plasma chamber and the second plasma chamber, the top
plate comprising a symmetric temperature regulation system between
the first plasma chamber and the second plasma chamber.
9. The plasma processing apparatus of claim 1, wherein at least one
of the first pedestal or the second pedestal comprise a plurality
of independent temperature regulation zones.
10. The plasma processing apparatus of claim 9, wherein each of the
plurality of independent temperature regulation zones comprise one
or more heating elements.
11. The plasma processing apparatus of claim 9, wherein each of the
plurality of independent temperature regulation zones comprise one
or more cooling channels.
12. The plasma processing apparatus of claim 9, wherein the
plurality of independent temperature regulation zones comprise a
plurality of radially divided zones.
13. The plasma processing apparatus of claim 9, wherein the
plurality of independent temperature regulation zones comprise a
plurality of azimuthally divided zones.
14. The plasma processing apparatus of claim 1, wherein at least
one of the first pedestal or the second pedestal are movable in a
vertical direction to adjust a vertical position of a
workpiece.
15. The plasma processing apparatus of claim 1, wherein at least
one of the first pedestal or the second pedestal comprise one or
more lift pins operable to adjust a vertical position of a
workpiece.
16. A top plate for a plasma strip tool comprising a first plasma
chamber and a second plasma chamber, the top plate comprising a
symmetric temperature regulation system, the symmetric temperature
regulation system comprising cooling channel having an inlet in a
central portion of the top plate between a first portion associated
with the first plasma chamber and a second portion associated with
the second plasma chamber, the cooling channel having one or more
outlets located proximate the inlet between the first portion and
the second portion.
17. The top plate of claim 16, wherein the cooling channel
comprises a common channel that passes between the first portion of
the top plate and the second portion of the top plate.
18. A plasma strip tool, comprising: a processing chamber; a first
pedestal in the processing chamber operable to support a workpiece,
the first pedestal defining a first processing station; a second
pedestal in the processing chamber operable to support a workpiece,
the second pedestal defining a second processing station; a first
plasma chamber disposed above the first processing station; a
second plasma chamber disposed above the second processing station;
a first separation grid separating the first plasma chamber from
the processing chamber; a second separation grid separating the
second plasma chamber from the processing chamber; a first
inductive plasma source operable to generate a plasma in the first
plasma chamber; a second inductive plasma source operable to
generate a plasma in the second plasma chamber; a first concentric
pump port located beneath the first pedestal; a second concentric
pump port located beneath the second pedestal.
19. The plasma strip tool of claim 18, wherein the tool further
comprises a common pump coupled to the first concentric pump port
and the second concentric pump port.
20. The plasma strip tool of claim 18, wherein the tool further
comprises a wall separating the first pedestal and the second
pedestal, the wall comprising one or more heating element or one or
more cooling channels.
Description
PRIORITY CLAIM
[0001] The present application claims the benefit of priority of
U.S. Provisional Patent Application No. 62/610,588, entitled
"Plasma Strip Tool with Uniformity Control," filed on Dec. 27,
2017, which is incorporated herein by reference. The present
application claims the benefit of priority of U.S. Provisional
Patent Application No. 62/517,365, entitled "Plasma Strip Tool with
Uniformity Control," filed on Jun. 9, 2017, which is incorporated
herein by reference for all purposes.
FIELD
[0002] The present disclosure relates generally to apparatus,
systems, and methods for processing one or more substrates using a
plasma source
BACKGROUND
[0003] Plasma processing is widely used in the semiconductor
industry for deposition, etching, resist removal, and related
processing of semiconductor wafers and other substrates. Plasma
sources (e.g., microwave, ECR, inductive, etc.) are often used for
plasma processing to produce high density plasma and reactive
species for processing substrates. Plasma strip tools can be used
for strip processes, such as photoresist removal. Plasma strip
tools can include one or more plasma chambers where plasma is
generated and one or more separate processing chambers where the
one or more substrates are processed. The one or more processing
chambers can be "downstream" of the one or more plasma chambers
such that there is no direct exposure of the one or more substrate
to the plasma. Separation grid(s) can be used to separate the one
or more processing chambers from the one or more plasma chambers.
The separation grids can be transparent to neutral species but not
transparent to charged particles from the plasma. The one or more
separation grids can include a sheet of material with holes.
[0004] Uniformity control in plasma strip tools can be important
for improved performance (e.g., improved ash rate performance).
Uniformity can be difficult to tune in a plasma strip tool without
manipulating process parameters, such gas pressure and flow, and RF
power provided to induction coils used to generate the plasma.
Uniformity control can be particularly important when matching
performance parameters of separate plasma processing heads in
plasma strip tool having a plurality of plasma processing heads,
such as a twin chamber plasma strip tool.
SUMMARY
[0005] Detailed discussion of embodiments directed to one of
ordinary skill in the art are set forth in the specification, which
makes reference to the appended figures, in which:
[0006] One example aspect of the present disclosure is directed to
a plasma processing apparatus. The apparatus includes a processing
chamber. The apparatus includes a first pedestal in the processing
chamber operable to support a workpiece. The first pedestal can
define a first processing station. The plasma processing apparatus
can include a second pedestal in the processing chamber operable to
support a workpiece. The second pedestal can define a second
processing station. The apparatus can include a first plasma
chamber disposed above the first processing station. The first
plasma chamber can be associated with a first inductive plasma
source. The first plasma chamber can be separated from the
processing chamber by a separation grid. The apparatus can include
a second plasma chamber disposed above the second processing
station. The second plasma chamber can be associated with a second
inductive plasma source. The second plasma chamber can be separated
from the processing chamber by a separation grid.
[0007] Other example aspects of the present disclosure are directed
to systems, methods, processes, apparatus, and devices for plasma
strip tool uniformity.
[0008] These and other features, aspects and advantages of various
embodiments will become better understood with reference to the
following description and appended claims. The accompanying
drawings, which are incorporated in and constitute a part of this
specification, illustrate embodiments of the present disclosure
and, together with the description, serve to explain the related
principles.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Detailed discussion of embodiments directed to one of
ordinary skill in the art are set forth in the specification, which
makes reference to the appended figures, in which:
[0010] FIG. 1 depicts an example twin chamber plasma processing
apparatus according to example embodiments of the present
disclosure;
[0011] FIG. 2 depicts a plan view of an example processing chamber
of a twin chamber plasma processing apparatus;
[0012] FIG. 3 depicts a plan view of an example processing chamber
of a twin chamber plasma processing apparatus according to example
embodiments of the present disclosure;
[0013] FIG. 4 depicts a plan view of an example twin chamber plasma
processing apparatus according to example embodiments of the
present disclosure;
[0014] FIG. 5 depicts a plan view of an example twin chamber plasma
processing apparatus according to example embodiments of the
present disclosure;
[0015] FIGS. 6(a), 6(b) and 6(c) depicts example vertical
positioning of a pedestal to adjust a distance between a separation
grid and a substrate in a plasma processing apparatus according to
example embodiments of the present disclosure;
[0016] FIGS. 7(a) and 7(b) depicts example vertical positioning of
one or more lift pins to adjust a distance between a separation
grid and a substrate in a plasma processing apparatus according to
example embodiments of the present disclosure;
[0017] FIGS. 8(a), 8(b) and 8(c) depict a pedestal with example
independent heating zones according to example embodiments of the
present disclosure;
[0018] FIG. 9 depicts a top plate for a twin chamber plasma
processing apparatus; and
[0019] FIG. 10 depicts a top plate for a twin chamber plasma
processing apparatus according to example embodiments of the
present disclosure;
DETAILED DESCRIPTION
[0020] Reference now will be made in detail to embodiments, one or
more examples of which are illustrated in the drawings. Each
example is provided by way of explanation of the embodiments, not
limitation of the present disclosure. In fact, it will be apparent
to those skilled in the art that various modifications and
variations can be made to the embodiments without departing from
the scope or spirit of the present disclosure. For instance,
features illustrated or described as part of one embodiment can be
used with another embodiment to yield a still further embodiment.
Thus, it is intended that aspects of the present disclosure cover
such modifications and variations.
[0021] Example aspects of the present disclosure are directed to
uniformity control in a plasma processing apparatus, such as a
plasma strip tool. In some embodiments, aspects of the present
disclosure can be used to improve uniformity in plasma strip tools
with multiple processing stations (e.g., capable of processing
multiple workpieces), such as in twin chamber strip tools.
[0022] For instance, a plasma processing apparatus can include a
processing chamber and at least two plasma chambers (e.g., a first
plasma chamber and a second plasma chamber). The processing chamber
can include a first pedestal (e.g., pedestal) defining a first
processing station for a workpiece and a second pedestal defining a
second processing station for a workpiece. In some embodiments, the
first pedestal and/or the second pedestal do not include an
electrostatic chuck.
[0023] A first plasma chamber for generating a plasma can be
disposed above the first processing station. A second plasma
chamber for generating a plasma can be disposed above the second
processing station. The first plasma chamber can be associated with
a first inductive plasma source (e.g., an induction coil) that when
energized with RF energy generates a plasma in a process gas in the
first plasma chamber. The second plasma chamber can be associated
with a second inductive plasma source (e.g., an induction coil)
that when energized with RF energy generates a plasma in a process
gas in the second plasma chamber.
[0024] Ions and radicals generated in the plasma in the first
plasma chamber can be passed through a separation grid. The
separation grid can filter out the ions and allow passage of
neutral particles for exposure to a workpiece at the first
processing station to perform a surface treatment process, such as
a photoresist removal. Similarly, ions and radicals generated in
the plasma in the second plasma chamber can be passed through a
separation grid. The separation grid can filter out the ions and
allow passage of neutral particles for exposure to a workpiece at
the second processing station to perform a surface treatment
process, such as photoresist removal.
[0025] Example embodiments of the present disclosure can be used to
provide uniformity tunability in a plasma strip tool using features
that can provide for one or more of tunability of radial
uniformity, azimuthal uniformity, and/or vertical uniformity.
Radial uniformity can refer to uniformity in a radial direction
extending between a center portion of a workpiece processed in the
plasma processing apparatus to a peripheral portion of a workpiece
processed in the plasma processing apparatus. Azimuthal uniformity
can refer to process uniformity at different azimuthal positions
around a workpiece processed in the plasma processing apparatus.
Vertical tunability can refer to the ability to affect process
uniformity through vertical movement of a workpiece in the
processing chamber of a plasma processing apparatus.
[0026] Azimuthal uniformity can be difficult to address in certain
multi-chamber (e.g., twin chamber) plasma processing apparatus
designs. For instance, as discussed above, a twin chamber plasma
processing apparatus can include a common pedestal with two
different processing portions for workpiece temperature regulation.
Due to extra thermal mass in between the processing portions
between the substrates, azimuthal uniformity can be difficult to
adjust.
[0027] According to example aspects of the present disclosure,
azimuthal uniformity can be improved using individual pedestals
(e.g., heating pedestals) for the substrates. A common pressure
equalizing baffle can be provided in conjunction with the
individual heating pedestals for azimuthal uniformity improvement.
In some embodiments, bottom concentric individual pumping with a
common pump can be used in conjunction with individual heating
pedestals for azimuthal uniformity improvement. In some
embodiments, for instance, azimuthal uniformity can be implemented
by rotating a pedestal supporting a substrate during processing of
the substrate (e.g., during a strip process).
[0028] According to example aspects of the present disclosure,
radial uniformity can be tuned, for instance, using a pedestal with
a plurality of independent temperature regulation zones. Each
temperature regulation zone can include one or more heating
elements for heating a workpiece. In addition and/or in the
alternative, each temperature regulation zone can include one or
more cooling channels for circulating a fluid (e.g., a gas, water,
cooling fluid, etc.) to cool the workpiece. In some embodiments,
the pedestal may not include an electrostatic chuck.
[0029] In some embodiments, a pedestal used to support a substrate
in the processing chamber of the plasma processing apparatus can
include multiple temperature regulations zones with each zone used
to control heating and/or cooling of a different radial and/or
azimuthal portion of the workpiece. For instance, a heating element
located within each zone can be independently controlled to affect
uniformity of the strip process in the plasma processing apparatus.
In some embodiments, the pedestal can have a center temperature
regulation zone and a peripheral temperature regulation zone. In
some embodiments, the pedestal can have three or more radially
separated temperature regulation zones. In some embodiments, the
pedestal can be divided azimuthally into quadrants or other
subdivision to provide multiple temperature regulation zones. More
or fewer temperature regulation zones can be used without deviating
from the scope of the present disclosure.
[0030] In some embodiments, uniformity can be vertically tuned by
adjusting the distance between the workpiece and the plasma chamber
or separation grid in a plasma processing apparatus. For instance,
a pedestal supporting the substrate can be moved in a vertical
direction to adjust the distance between the workpiece and the
separation grid. In addition and/or in the alternative, the height
of one or more lift pins supporting the substrate can be adjusted
to control the distance between the separation grid and the
workpiece.
[0031] A twin chamber plasma processing apparatus can include a
common top plate located above two separate plasma chambers (e.g.,
plasma heads) for plasma generation. In some embodiments, the top
plate can include a symmetric temperature regulation system. The
symmetric temperature regulation system can include one or more
heating elements and/or one or more cooling channels. According to
example aspects of the present disclosure, a symmetric temperature
regulation system can be employed to reduce a top plate temperature
difference between the two plasma chambers. In some embodiments,
each plasma chamber can be associated with its own temperature
regulation system to enhance uniformity between the plasma
sources.
[0032] One example embodiments of the present disclosure is
directed to a plasma processing apparatus. The apparatus includes a
processing chamber. The apparatus includes a first pedestal in the
processing chamber operable to support a workpiece. The first
pedestal defines a first processing station. The apparatus includes
a second pedestal in the processing chamber operable to support a
workpiece. The second pedestal defines a second processing station.
The apparatus includes a first plasma chamber disposed above the
first processing station. The apparatus includes a second plasma
chamber disposed above the second processing station.
[0033] In some embodiments, the processing chamber can have a wall
separating the first pedestal from the second pedestal. In some
embodiments, the wall can include a wall temperature regulation
system. The wall temperature regulation system can include one or
more heating elements and/or one or more cooling channels. The
first pedestal and the second pedestal can each have their own
independent processing chamber. In some embodiments, the plasma
processing apparatus can include a pressure equalizing baffle
operable to maintain pressure between the first processing station
and the second processing station.
[0034] In some embodiments, the apparatus includes a first
concentric pump port located beneath the first pedestal. The
apparatus includes a second concentric pump port located beneath
the second pedestal. The plasma processing apparatus can include a
common pump coupled to the first concentric pump port and the
second concentric pump port.
[0035] In some embodiments, the apparatus includes a first
separation grid separating the first plasma chamber from the
processing chamber. The apparatus includes a second separation grid
separating the second plasma chamber from the processing chamber.
In some embodiments, the apparatus includes a common separation
grid separating both the first plasma chamber and the second plasma
chamber from the processing chamber.
[0036] In some embodiments, the plasma processing apparatus
includes a top plate disposed above the first plasma chamber and
the second plasma chamber. The top plate comprises a symmetric
temperature regulation system between the first plasma chamber and
the second plasma chamber.
[0037] In some embodiments, at least one of the first pedestal or
the second pedestal includes a plurality of independent temperature
regulation zones. The plurality of independent temperature
regulation zones can include a plurality of radially divided zones
(e.g., a center zone and a peripheral zone). The plurality of
temperature regulation zones can include a plurality of azimuthally
divided zones (e.g., quadrants).
[0038] In some embodiments, at least one of the first pedestal or
the second pedestal are movable in a vertical direction to adjust a
vertical position of a workpiece relative to a separation grid. In
some embodiments, at least one of the first pedestal or the second
pedestal include one or more lift pins operable to adjust a
vertical position of a workpiece relative to a separation grid.
[0039] Another example embodiment of the present disclosure is
directed to a top plate for a plasma strip tool comprising a first
plasma chamber and a second plasma chamber. The top plate includes
a symmetric cooling channel. The symmetric cooling channel includes
an inlet in a central portion of the top plate between a first
portion associated with the first plasma chamber and a second
portion of the top plate associated with the second plasma chamber.
The cooling channel includes one or more outlets located proximate
the inlet between the first portion and the second portion. In some
embodiments, the symmetric cooling channel includes a common
channel that passes between the first portion of the top plate and
the second portion of the top plate.
[0040] Another example embodiment of the present disclosure is
directed to a plasma strip tool. The tool includes a processing
chamber. The tool includes a first pedestal in the processing
chamber operable to support a workpiece. The first pedestal defines
a first processing station. The tool includes a second pedestal in
the processing chamber operable to support a workpiece. The second
pedestal defines a second processing station. The tool includes a
first plasma chamber disposed above the first processing station.
The tool includes a second plasma chamber disposed above the second
processing station. The tool includes a first separation grid
separating the first plasma chamber from the processing chamber.
The tool includes a second separation grid separating the second
plasma chamber from the processing chamber. The tool includes a
first inductive plasma source operable to generate a plasma in the
first plasma chamber. The tool includes a second inductive plasma
source operable to generate a plasma in the second plasma chamber.
The tool includes a first concentric pump port located beneath the
first pedestal. The tool includes a second concentric pump port
located beneath the second pedestal.
[0041] In some embodiments, the tool includes a common pump coupled
to the first concentric pump port and the second concentric pump
port. In some embodiments, the tool includes a wall separating the
first pedestal and the second pedestal. The wall can include a
temperature regulation system. In some embodiments, the tool
includes a top plate coupled to the first plasma chamber and the
second plasma chamber. The top plate can include a symmetric
cooling channel.
[0042] Aspects of the present disclosure are discussed with
reference to a "wafer" or semiconductor wafer for purposes of
illustration and discussion. Those of ordinary skill in the art,
using the disclosures provided herein, will understand that the
example aspects of the present disclosure can be used in
association with any semiconductor substrate or other suitable
substrate. In addition, the use of the term "about" in conjunction
with a numerical value is intended to refer to within 10% of the
stated numerical value. In addition, the terms "plasma chamber" and
"plasma head" are intended to be used interchangeably herein. The
term "pedestal" refers to any structure used to support a
workpiece. In some embodiments, a pedestal does not include an
electrostatic chuck.
[0043] With reference now to the FIGS., example embodiments of the
present disclosure will now be set forth. The example embodiments
are discussed herein with respect to a twin chamber plasma
processing apparatus having two plasma chambers connected to a
single processing chamber having two pedestals. Those of ordinary
skill in the art will understand that various configurations of
plasma processing apparatus can be used in accordance with the
present disclosure. For example, plasma processing apparatus having
more than two plasma chambers, such as three plasma chambers, four
plasma chambers, or any other suitable number of plasma chambers
can be used in accordance with the present disclosure.
Additionally, and/or alternatively, plasma processing apparatus
having more than one processing chamber can be used in accordance
with the present disclosure. For example, a plasma processing
apparatus having a plurality of processing chambers each with an
associated plasma chamber can be used in accordance with the
present disclosure. As another example, a plurality of processing
chambers each having a plurality of associated plasma chambers can
be used in accordance with the present disclosure. As another
example, a processing chamber having more than two can be used in
accordance with the present disclosure.
[0044] FIG. 1 depicts an example multi-chamber plasma processing
apparatus 100 according to example embodiments of the present
disclosure. The processing apparatus 100 includes a processing
chamber 110 and a first plasma chamber 120 (e.g., first plasma
head) that is separate from the processing chamber 110. The plasma
processing apparatus 100 can include a second plasma chamber 140
(e.g., second plasma head) that can be substantially identical to
the first plasma chamber 120. A top cap 124 can be disposed above
the first plasma chamber 120 and the second plasma chamber 140.
[0045] The first plasma chamber 120 can include a dielectric
sidewall 122. The top plate 124 and dielectric sidewall 124 can
form a first plasma chamber interior 125. Dielectric sidewall 122
can be formed from any suitable dielectric material, such as
quartz.
[0046] The plasma processing apparatus 100 can include a first
inductively coupled plasma source 135 configured to generate a
plasma in a process gas provided to the first plasma chamber
interior 125. The first inductively coupled plasma source 135 can
include induction coil 130 disposed about the dielectric sidewall
122. The induction coil 130 can be coupled to an RF power generator
134 through a suitable matching network 132. Reactant and/or
carrier gases can be provided to the chamber interior from a gas
supply (not illustrated). When the induction coil 130 is energized
with RF power from the RF power generator 134, a substantially
inductive plasma is induced in the first plasma chamber interior
125. In some embodiments, the first plasma chamber 120 can include
a grounded Faraday shield to reduce capacitive coupling of the
induction coil 130 to the plasma.
[0047] The second plasma chamber 140 can include a dielectric
sidewall 142. The top plate 124 and dielectric sidewall 142 can
form a second plasma chamber interior 145. Dielectric sidewall 142
can be formed from any suitable dielectric material, such as
quartz.
[0048] The plasma processing apparatus 100 can include a second
inductively coupled plasma source 155 configured to generate a
plasma in a process gas provided to the second plasma chamber
interior 145. The second inductively coupled plasma source 155 can
include induction coil 150 disposed about the dielectric sidewall
142. The induction coil 150 can be coupled to an RF power generator
154 through a suitable matching network 152. Reactant and/or
carrier gases can be provided to the chamber interior 145 from a
gas supply (not illustrated). When the induction coil 150 is
energized with RF power from the RF power generator 154, a
substantially inductive plasma is induced in the second plasma
chamber interior 145. In some embodiments, the second plasma
chamber 150 can include a grounded Faraday shield to reduce
capacitive coupling of the induction coil 150 to the plasma.
[0049] A first separation grid 116 can separate the first plasma
chamber 120 from the processing chamber 110. The first separation
grid 116 can be used to perform ion filtering of particles
generated by plasma in the first plasma chamber 120. Particles
passing through the first separation grid 116 can be exposed to a
workpiece (e.g., a semiconductor wafer) in the processing chamber
for surface treatment of the workpiece (e.g., photoresist
removal).
[0050] More particularly, in some embodiments, the first separation
grid 116 can be transparent to neutral species but not transparent
to charged particles from the plasma. For example, charged
particles or ions can recombine on walls of the first separation
grid 116. The first separation grid 116 can include one or more
grid plates of material with holes distributed according to a hole
pattern for each sheet of material. The hole patterns can be the
same or different for each grid plate.
[0051] For example, the holes can be distributed according to a
plurality of hole patterns on a plurality of grid plates arranged
in a substantially parallel configuration such that no hole allows
for a direct line of sight between the plasma chamber and the
processing chamber to, for example, reduce or block UV light.
Depending on the process, some or all of the grid can be made of a
conductive material (e.g., Al, Si, SiC, etc.) and/or non-conductive
material (e.g., quartz, etc.). In some embodiments, if a portion of
the grid (e.g. a grid plate) is made of a conductive material, the
portion of the grid can be grounded.
[0052] A second separation grid 166 can separate the second plasma
chamber 140 from the processing chamber 110. The second separation
grid 166 can be used to perform ion filtering of particles
generated by plasma in the second plasma chamber 140. Particles
passing through the second separation grid 166 can be exposed to a
workpiece (e.g., a semiconductor wafer) in the processing chamber
for surface treatment of the workpiece (e.g., photoresist
removal).
[0053] More particularly, in some embodiments, the second
separation grid 166 can be transparent to neutral species but not
transparent to charged particles from the plasma. For example,
charged particles or ions can recombine on walls of the second
separation grid 166. The second separation grid 166 can include one
or more grid plates of material with holes distributed according to
a hole pattern for each sheet of material. The hole patterns can be
the same or different for each grid plate.
[0054] For example, the holes can be distributed according to a
plurality of hole patterns on a plurality of grid plates arranged
in a substantially parallel configuration such that no hole allows
for a direct line of sight between the plasma chamber and the
processing chamber to, for example, reduce or block UV light.
Depending on the process, some or all of the grid can be made of a
conductive material (e.g., Al, Si, SiC, etc.) and/or non-conductive
material (e.g., quartz, etc.). In some embodiments, if a portion of
the grid (e.g. a grid plate) is made of a conductive material, the
portion of the grid can be grounded.
[0055] The processing chamber 110 can include one or more pedestals
(e.g., substrate holders) operable to hold one or more workpieces
during processing. FIG. 2 depicts a plan view of a common heating
pedestal 112 that can be used in a multi-chamber plasma processing
apparatus The common heating pedestal 112 can include two
processing stations 112a and 112b for processing workpieces. The
common heating pedestal 112 can make it difficult to tune azimuthal
uniformity of workpieces at processing stations 112a and 112b due
to the extra thermal mass 113 of the pedestal 112 between the
processing stations 112a and 112b.
[0056] To improve azimuth uniformity, a processing chamber 110
according to example aspects of the present disclosure can include
a first pedestal 212 (e.g., a heated pedestal) defining a first
processing station for supporting a first workpiece 214 beneath the
first plasma chamber 120 for processing the workpiece 214. The
processing chamber 110 can include a second pedestal 222 (e.g.,
heated pedestal) defining a second processing station for
supporting a second workpiece 224 beneath the second plasma chamber
140 for processing the workpiece 224 at a second processing
station. The first pedestal 212 is separated from the second
pedestal 222 such that there is no solid mass connecting the first
pedestal 212 and the second pedestal 222.
[0057] In some embodiments, an optional wall 240 can separate the
first pedestal 212 and the second pedestal 222. The wall 240 can
include a wall temperature regulation system 242. The wall
temperature regulation system 242 can include one or more heating
elements. The wall temperature regulation system 242 can include
one or more cooling channels operable to circulate fluid through
the wall.
[0058] The use of independent pedestals 212 and 222 can reduce
azimuthal non-uniformities resulting from use of a common heating
pedestal 112. In some embodiments, the pedestals 212 and 222 do not
include an electrostatic chuck.
[0059] FIG. 3 depicts a plan view of an example processing chamber
110 including a first pedestal 212 and a second pedestal 222
according to example embodiments of the present disclosure. The
first pedestal 212 can be associated with a first processing
station for a workpiece 214. The second pedestal 222 can be
associated with a second processing station for workpiece 224. The
first pedestal 212 and the second pedestal 222 can each be
associated with its own independent respective plasma chamber
(e.g., plasma head). The first pedestal 212 and the second pedestal
222 can be located in the same processing chamber 110. A common
pump port can be associated with the processing chamber 110. A
pressure equalizing baffle 250 can be used to maintain pressure in
the processing chamber 110.
[0060] FIGS. 4 and 5 depict an example plasma processing apparatus
with independent pedestals according to example embodiments of the
present disclosure. The first pedestal 212 can be associated with a
first processing station. The second pedestal 222 can be associated
with a second processing station. The first pedestal 212 and the
second pedestal 222 can each be associated with its own independent
respective plasma chamber (e.g., plasma head). The first pedestal
212 and the second pedestal 222 can be disposed in separate
processing chambers. For instance, first pedestal 212 can be
disposed in first processing chamber 260. The second pedestal 222
can be disposed in second processing chamber 270. The first
processing chamber 260 can have chamber walls and a slit door 262
to allow placement of a workpiece on the pedestal 212. The second
processing chamber 270 can have chamber walls and a slit door 272
to allow placement of a substrate on the second pedestal 222.
[0061] A first pump port 310 (e.g., a concentric pump port) can be
located beneath the first pedestal 212. A second pump port 320
(e.g., a concentric pump port) can be located beneath the second
pedestal 222. As shown in FIG. 5, the first pump port 310 and the
second pump port 320 can be coupled to a common plenum 330 having a
pump. In this way, the pump port 310 and the pump port 320 can be
coupled to a common pump.
[0062] In some embodiments, a plasma processing apparatus can have
features for vertical tunability of process uniformity. FIGS.
6(a)-6(c) depict example vertical positioning of a pedestal to
adjust a distance between a separation grid/plasma chamber and a
workpiece in a plasma processing apparatus according to example
embodiments of the present disclosure. In FIG. 6(a), the pedestal
212 is positioned in a first vertical position so that the
workpiece is a first distance d1 from the separation grid
116/plasma chamber. The position of the pedestal 212 shown in FIG.
6(a) can be associated with a workpiece loading operation. In FIG.
6(b), the pedestal 212 is positioned in a second vertical position
so that the workpiece is a second distance d2 (e.g., no more than 2
mm) from the separation grid 116/plasma chamber. The second
distance d2 can be less than the first distance d1. In FIG. 6(c),
the pedestal 212 is in a third vertical position so that the
workpiece is a third distance d3 from the separation grid. The
third distance d3 can be greater the first distance d1 and the
second distance d2. Other vertical positions are within the scope
of the present disclosure.
[0063] FIGS. 7(a)-7(b) depict example vertical positioning of one
or more lift pins to adjust a distance between a separation
grid/plasma source and a workpiece in a plasma processing apparatus
according to example embodiments of the present disclosure. In FIG.
7(a), the lift pin(s) 342 can be in a first vertical position so
that the workpiece is a first distance d4 from the separation grid
116/plasma source. The position of the workpiece shown in FIG. 7(a)
can be associated with a workpiece loading operation. In FIG. 7(b),
the lift pin(s) 342 can be in a second vertical position so that
the workpiece is a second distance d2 from the separation grid
116/plasma source. The second distance d2 can be less than the
first distance d1. Other vertical positions are within the scope of
the present disclosure.
[0064] In some embodiments, each pedestal can be used to control
the temperature of the workpiece during processing. The temperature
of the workpiece can be controlled, for instance, to be in the
range of about 20 degrees Celsius to about 450 degrees Celsius.
[0065] In some embodiments, any of the pedestals described herein
can have a plurality of temperature regulations zones for tuning
process uniformity. Each temperature regulation zone can include
one or more heating elements and/or one or more cooling channels.
The independent temperature regulation zones can be controlled to
provide for temperature gradients between zones. The temperature
gradient can be, for instance, about 30 degrees Celsius or less,
such as about 20 degrees Celsius or less, such as about 10 degrees
Celsius or less, such as about 5 degrees Celsius or less, such as
about 2 degrees Celsius or less.
[0066] FIGS. 8(a)-8(c) depict a pedestal 212 with example
independent temperature regulation zones according to example
embodiments of the present disclosure. More particularly, FIG. 8(a)
depicts a pedestal 212 with a single temperature regulation zone.
FIG. 8(b) depicts a pedestal 212 with three radially separated
independent temperature regulation zones. More particularly, the
pedestal includes a center temperature regulation zone 416 and a
peripheral temperature regulation zone 414. In addition, the
pedestal includes an outer temperature regulation zone 418 outside
of the peripheral temperature regulation zone 414.
[0067] FIG. 8(c) depicts a pedestal 212 with three radially
separated temperature regulation zones (e.g., center temperature
regulation zone 416, peripheral temperature regulation zone 414,
outer temperature regulation zone 418) that is also divided
azimuthally into quadrants, such as first quadrant 422, second
quadrant 424, third quadrant 426, and fourth quadrant 428. The
division of temperature regulation zones as shown in FIG. 8(c) can
result in twelve different independent temperature regulation
zones. Other divisions of the pedestal in a radial fashion and/or
an azimuthal fashion or other manner are within the scope of the
present disclosure.
[0068] Example aspects of the present disclosure are directed to a
top cap for a multi-chamber plasma processing apparatus with more
uniform cooling. The top cap can include a symmetric temperature
regulation system (e.g., a cooling channel) to provide for improved
uniformity between processing chambers.
[0069] More particularly, FIG. 9 depicts a cooling channel 520 for
circulating a cooling fluid through a top plate 124 of a twin
chamber plasma processing apparatus having a first plasma chamber
120 and a second plasma chamber 140. As shown, the inlet 522 and
outlet 524 of the cooling channel 520 is located proximate the
second plasma chamber 140. Because the cooling fluid (e.g., water
or other cooling fluid) circulating through the channel 520 may be
warmed by the second plasma chamber 140 prior to reaching the
portion of the top plate 124 associated with the first plasma
chamber 120, the portion of the top plate 124 associated with the
first plasma chamber 120 may be warmer than the portion of the top
plate 124 associated with the second plasma chamber 140.
[0070] FIG. 10 depicts a cooling channel 530 for circulating a
cooling fluid through a top plate 124 of a twin chamber plasma
processing apparatus according to example embodiments of the
present disclosure. As illustrated, the top plate 124 includes a
symmetric cooling channel 530 (e.g. symmetric about an axis passing
between the first plasma chamber 120 and the second plasma chamber
140). The symmetric cooling channel 530 includes an inlet 536
located in a central portion of the top plate 124 between the first
plasma chamber 120 and the second plasma chamber 140. The channel
530 includes a common portion 537 that passes between the first
plasma chamber 120 and the second plasma chamber 140. The channel
530 includes a first branch 538 that extends from the common
portion 537 around the first plasma chamber 120 to a first outlet
542. The first outlet 542 can be located between the first plasma
chamber 120 and the second plasma chamber 140. The channel 530
includes a second branch 539 that extends from the common portion
537 around the second plasma chamber 140 a second outlet 544. The
second outlet 544 can be located between the first plasma chamber
120 and the second plasma chamber 140. The first outlet 542 and/or
the second outlet 544 can be located proximate to the inlet 536 for
the channel 530.
[0071] While the present subject matter has been described in
detail with respect to specific example embodiments thereof, it
will be appreciated that those skilled in the art, upon attaining
an understanding of the foregoing may readily produce alterations
to, variations of, and equivalents to such embodiments.
Accordingly, the scope of the present disclosure is by way of
example rather than by way of limitation, and the subject
disclosure does not preclude inclusion of such modifications,
variations and/or additions to the present subject matter as would
be readily apparent to one of ordinary skill in the art.
* * * * *